The present invention relates to a magnetic head for perpendicular recording and a magnetic recording and reproduction apparatus comprising the magnetic head for perpendicular recording.
A magnetic recording and reproduction apparatus comprises a magnetic recording medium and a magnetic head and reads and writes data on the magnetic recording medium with the magnetic head. To increase the recording capacity per unit area of the magnetic recording medium, the surface recording density must be raised. However, according to the current longitudinal recording system, when the bit length to be recorded is small, the surface recording density cannot be raised due to the thermal fluctuation of the magnetization of the medium. A solution to this problem is a perpendicular recording system for recording a magnetization signal in a direction perpendicular to the medium.
The perpendicular recording system is divided into two subsystems: one using a double-layer perpendicular recording medium comprising a soft under layer and the other using a single-layer perpendicular recording medium having no under layer as the recording medium. When the double-layer perpendicular recording medium is used as the recording medium, a stronger magnetic field can be applied to the medium by using a so-called “single-pole head” having a main pole and an auxiliary pole to record data. In consideration of a case where the head has a skew angle, the shape of the air bearing surface of the main pole is desirably trapezoidal with a narrower width on the leading side.
FIGS. 4(a) and 4(b) are structural diagrams of a prior art magnetic head having a single-pole head, wherein FIG. 4(a) is a sectional view and FIG. 4(b) is a plan view when seen from the trailing side. As shown in FIGS. 4(a) and 4(b), the prior art magnetic head comprises a lower shield 8, read element 7, upper shield 9, auxiliary pole 3, thin film coil 2 and main pole 1 in the order named from the traveling direction of the head (leading side). The lower shield 8, read element 7 and upper shield 9 constitute a read head 24 whereas the auxiliary pole 3, thin film coil 2 and main pole 1 constitute a write head (single-pole head) 25. The recording medium has a soft under layer 20 below the magnetic recording layer 19.
JP-A No. 2000-20913 (Patent document 1) discloses a structure that a discontinuous portion is formed in a magnetic film pattern forming a magnetic path in a magnetic recording head.